Dehydrating ammonia vapors



Jan. 3, 1928.

l c. COOPER ET AL nsaymu'rme menu VAPORS Filed Feb. 5. 1927,

Patented Jan. 3, 1928.

' UNITED STATES PATENT OFFICE.

CHARLES COOPER AND DANIEL MAYON HENSHAW, OF HUDDERSFIELD, ENGLAND, AS- SIGNORS TO W. C. HOLMES AND COMPANY,,LIMITED, OF HUDDERSFIELD, ENGLAND.

DEHYDRATING AMMONIA VAPORS.

Application filed February 5, 1927, Serial No. 166,253, and in Great Britain December 16, 1925.

This invention relates to the treatment of mixtures of ammonia and water vapor in order to efi'ect the separation therefrom of a greater or less proportion of the contained moisture.

The invention consists broadly in bringing the ammonia associated with water into intimate contact with liquid materials having a selective aiiinity for the water.

Preferably in accordance with the invention the ammonia mixture is caused to flow in counter-current to the material having a. selective aflinity for the water in the mixture.

.Thus in accordance with the invention in treating ammonia liquor the vapors arising from an ammonia still are brought into accordance with the invention.

intimate contact with a liquid material having a selective affinity for the water component, preferably by causing the vapors and the liquid to flow in counter-current.

A variety of materials possessing a selective aflinity for water may be employed in A solution of potassium carbonate is conveniently used where mixtures containing ammonia are treated, and, as will be understood, the solution employed in the treatment of mixtures containing ammonia is preferably maintained at a sufficiently high temperature to reduce further its capacity to absorb ammonia. Should any considerable proportion of ammonia be absorbed by the material possessing a selective afiinity for water means may be provided for recovering the ammonia so absorbed.

Where the invention is applied to the separation of moisture from mixtures of ammo nia, steam and other gases, such for instance as arise in the treatment of ammonia liquor, solutions of ammonia of high concentration may be obtained with simplified apparatus. Similarly the invention may be applied to the removal of moisture from such gases and the direct treatment of the gases to obtain ammonium salts, such for instance as sulphate of ammonia.

Further, the invention may be applied to the production of sublimed ammonium carbonate from still ases, and the process of producing ammonium salts inthe manner specified falls within the scope of the present application.

As an example of our process, the vapors arising from an ammonia still are caused to pass through a distillation or rectifying colit may be reconcentrated and returned to the,

column. 7

Suitable apparatus for use 1n the lnvention comprises essentially a column or tower,

means for introducing thereinto the mixture of vapors or vapors and gases to be treated, means for introducing into the column liquid material having a selective aflinity for water, means for bringing the said material into intimate contact with the vapor or vapors and gases introduced into the column, means for withdrawing from the column the material possessing a selective affinity for one of the constituents of the mixture, means for concentrating the said ma- "terial or expelling the water therefrom, and

means adapted to return the material after concentration or partial removal of the water to the column.

Certain constructionsin accordance with the invention are illustrated by way of example in the accompanying drawing, in which:

Figure 1 is a viewin section of a suitable construction.

In the drawing, a tower 1 is provided with a vapor inlet 2 and an outlet 3 and with a li uor outlet 4 leading to a tank 5'from whic extends a pipe 6 connectin the same with a pump 7 furnished with a delivery 8. The tower is provided with an overflow device 9. l

- In the construction illustrated the delivery 8 of the pump is arranged to elevate liquid 100 into the vessel 10 which at its base is providedwith a number of jets 11 adaptedto' direct the liquid discharged from the vessel 10 onto the walls of the tower down which liquid will run, being finally collected in the 1 5 channel 12 communicating, by the pipe 13 construction 14 adapted to cause the vapors introduced by way of the pipe 2 to make intimate contact with the liquid delivered 110 with a number of bubbling trays of known thereinto. The liquid in question, as above explained, will be a material having a selective affinity for one of the constituents of the mixture, for instance Water, and the material diluted with Water will collect in the base of the tower "from which it will be transferred by the pump, as above explained, to the vessel 10 and in travelling over the external surface of the tower the heat contained in the vapors will cause the Water the process and apparatus as above defined Without exceeding the scope of the present specification.

Having now described our invention, What newness we claim as new and desire to secure by Letters Patent is z- 1. The process of treating a mixture oi water vapor and ammonia "which comprises causing the mixture to flow in intimate contact and in counter current With a liquid material having a selective aiiinity for water and maintaining the liquid material at a relatively high temperature to reduce its ammonia-absorbing capacity.

2. A process according to claim 1, in which the liquid material is a solution of potassium carbonate.

In testimony whereof We have signed our names to this specification.

CHARLES CUOPER. DANIEL MAYON HENSHAW. 

